I'd appreciate any help, coz boilers ain't my strong point! The boiler won't start when I switch it on, therm on max. The fan light is on and boiler light is on. I hear a low humming noise. There's no pilot light and both the pilot light light and burner light are off. We had BG out a few months back when it wouldn't start, he unclipped the front, tapped then lubbed the fan and all was well. Any thoughts guys?